1. Field of the Invention
This invention relates generally to carts for supporting and containing vertically stacked units, and particularly relates to carts for supporting and containing newspaper bundles.
2. Description of the Related Art
The circulation of daily newspapers requires that every operation from printing of the newspapers to distribution be performed quickly and efficiently. Accordingly, loading and shipping newspapers to distributors must be performed quickly and efficiently without damaging the newspapers.
The loading operation stacks single newspapers after printing to form a bundle. The bundles, which may be secured with string for lateral support, are carried by a conveyor to a loading station and loaded onto a cart or other transport vehicle.
To increase the efficiency of the system, the conveyor contains apparatus for arranging bundles into an array and each array of bundles is loaded onto a cart as a layer, rather than individually loading each bundle. For example, the array may consist of a 2.times.2 or 2.times.3 array of bundles.
The handling of bundles becomes increasingly important as the bundle size and number of bundle layers increase. Each newspaper bundle is approximately eleven inches in width and fourteen inches in length with an average height ranging from three to fifteen inches and a maximum height of approximately eighteen inches. At this height, the newspaper bundles weigh approximately fifty pounds.
Inserting fliers or magazines in newspapers causes the bundles to be fatter in the middle. As a result, the bundles are unstable lengthwise and must be stabilized in the cart to prevent the bundles from falling out of the cart during and after loading.
Several types of carts have been used for handling newspaper bundles. The carts generally have a rectangular horizontal support with three vertical walls. The newspaper bundles are loaded onto the horizontal support through a open side of the cart. The carts typically included straps for retaining the bundles. After loading, an operator had to manually fasten the straps to the walls in an attempt to enclose the bundles in the cart. In addition to requiring substantial operator effort, the straps were generally ineffective in that the irregularly shaped bundles often fell out of the cart between the straps.
Other carts used doors, or a combination of doors and straps, which were opened by an operator during the loading process and closed in order to retain the bundles during transport. The operator closed and latched the doors together or latched the doors to the horizontal support. Latching the doors was sometimes difficult, thus increasing operator time and reducing system efficiency. The doors, which extended from the cart during loading, also impeded operator movement about the cart.
Another type of cart included a horizontal support, three vertical walls, and netting which covered the open side of the cart. However, in order to load this cart, the bundles had to be loaded from the top of the cart rather than the side, which was much more difficult, and thus more expensive than side loading.